Light Emitting Diodes (LEDs) are a very energy efficient electronic lighting source. The generation of LEDs emitted red light with a very small amount of illuminating power. However, modern LEDs can now generate light across the visible, ultraviolet, and infrared wavelengths. Furthermore, modern LEDs can be provided with a significant amount of current such that LEDs can produce enough light to be used as illumination sources.
LEDs present many advantages over traditional sources of lighting including energy efficiency, a longer lifetime, greater durability, a small form factor, and a very fast switching speed. These many advantages fueled the use of LEDs in a wide variety of applications. However, LEDs are still relatively expensive in up-front costs compared to incandescent and fluorescent light sources. Furthermore, LEDs generally require more precise current and heat management than traditional lighting sources. The first LEDs were used mainly as indicator lights on electronic equipment. LEDs have been ideal for portable electronics due to their low-energy usage and small form factor. However, in more recent years, the availability of new LED colors and increases in brightness have allowed LEDs to be used in many new applications.
The small size of LEDs and the ability to control the switching of LEDs using computers have allowed for the development of LED based display systems. Specifically, a two dimensional array of individually controlled LEDs can be used to display words and images. Thus, LEDs now provide the light source for many modern electronic scoreboards and very large scale video display systems such as the large video display systems seen at sports arenas and at New York City's Times Square.
Although LED-based display systems have proven to work very well, the inherent difficulties and expense involved in creating such LED based video display systems have limited the deployments of LED-based video display systems. Carefully metered and individually controlled electric power must be provided to each LED in a two dimensional array of LEDs that creates a LED based video display system. To construct a monochrome high definition display system with a resolution of 1920×1080 picture elements (pixels) requires that the system provide 2,073,600 individual LEDs with carefully controlled electrical power. To create a multi-color high definition display system, three different colored LEDs (red, green, and blue) are required for each individual pixel such that 6,220,800 individual LEDs must receive carefully controlled electrical power. Thus, the design and manufacture of such large scale video display systems is both complex and very expensive.
Due to the challenges of controlling so many independent LEDs, large LED based video display systems cost many millions of dollars such that only very high end applications, such as large sports arenas, are able to purchase large LED based video display systems. Public video display systems for other situations generally use smaller conventional display technologies associated with television displays or use much simpler display systems such as large electronic scoreboards with only limited pre-arranged LED patterns for displaying team scores and game time. It would therefore be desirable to simplify the task of designing and constructing LED based display and lighting systems.